Method and apparatus for producing bulky continuous filament yarn



Sept. 23, 1958 A. L. BREEN METHOD AND APPARATUS FOR PRODUCING BULKYCONTINUOUS FILAMENT YARN 4 Sheets-Sheet 1 Filed Aug. 20, 1953 INVENTORALVIN L. BREEN BY ATTORNEY Sept. 23 1958 A. L. BREEN METHOD ANDAPPARATUS FOR PRODUCING BULKY CONTINUOUS FILAMENT YARN Filed Aug. 20,1953 I 4 Sheets-Sheet 2 FIG. 9

BY Mam ATTORNEY Sept. 23, 1958 A. L. BREEN 2,852,906

METHOD AND APPARATUS FOR PRODUCING BULKY CONTINUOUS FILAMENT YARN FiledAug. 20, 1955 4 Sheets-$heet 3 INVENTOR ALVIN L. BREEN ATTORNEY Sept.23, 1958 A. L. BREEN METHOD AND APPARATUS FOR PRODUCING BULKY CONTINUOUSFILAMENT YARN Filed Aug. 20, 1953 4 Sheets-Sheet 4 TENSlON IN GRAMS TOINITIATE REMOVAL OF CONVOLUTIONS TWISTS IN TURNS PER INCH OF YARN FIG. 6

INVENTOR ALVIN L. BREEN ATTORNEY United States Patent Ofifice 2,852,906Patented Sept. .23, 1958 METHOD AND APPARATUS FOR PRODUCING BULKYCONTINUOUS FILAMENT YARN Alvin L. Breen, West Chester, Pa., assignor toE. L du Pont de Nemours and Company, Wilmington, Del., a. corporation ofDelaware Application August 20, 1953, Serial No. 375,372

11 Claims. (CI. 57-34) This invention relates to process and apparatusfor treating a bundle of continuous filaments, such as a yarn or thread,to produce a multifilament yarn of greatly increased bulk, and to thenovel bulky yarn produced. More particularly, the invention claimedherein relates to a process and apparatus for preparing a bulky yarncomposed of a plurality of individually convoluted filaments.

This application is a continuation-impart of my copending application,Serial No. 261,635, filed December 14, 1951 now Patent No. 2,783,609.

With the outstanding exception of silk, all natural animal, vegetableand mineral fibers exist in only relatively short lengths. Theproduction of yarn from such staple fiber is a time-consuming operationwhich usually requires a complex series of operations to align thefibers, combine them into an elongated bundle, and draw the bundle tosmaller diameter while twisting to prevent execessive slipping ofadjacent fibers past each other. Further spinning operations finallyproduce yarn of thread useful in textile operations.

All, or nearly all, artificial fibers are produced most easily ascontinuous filaments. Formation of continuous filaments into yarn ismuch simpler than staple processing. Continuous filament yarns may bemade very strong because of the absence of loose ends that are unable totransmit imposed stresses. However, because of their extreme uniformityand lack of discontinuities, conventional continuous filament yarns aremuch denser than their staple counterparts. The filaments lie closetogether in the yarn, and adjacent strands of continuous filament yarnin fabrics are closely spaced. This compactness limits the amount ofinsulating air space present. The lack of occluded air space greatlyrestricts the usefulness of such continuous filament fabrics. Lightness,covering effectiveness, and warmth-giving bulk are essential for manyuses. Hence a large amount of the total continuous filament productionof such fibers as viscose rayon, cellulose acetate, nylon andpolyacrylonitrile has cut into short lengths for spinning into stapleyarn.

Previous efforts to produce continuous filament yarn having thedesirable qualities of staple yarn have been unsuccessful. These effortshave been concerned primarily with modifying the internal structure ofthe filaments, as by physical or chemical distortion. Mechanicalcrimping or twisting of filaments has produced undulating or spiralledfibers, but the effect has been disappointing. Similar unsatisfactoryresults have been obtained by imparting motion to the spinning head andby chemical treatment of the spun filaments. All known methods have beenunsatisfactory for one reason or another, such as insuificientbulkiness, unsatisfactory distribution of stressbearing portions of thefilaments, undesirable modification of fiber properties, impermanence ofform, or complexity and expense of the operations.

It is an object of the present invention to provide continuous filamentyarn having a bulkiness at least as great as that of staple yarn spunfrom comparable fibers and having the same average number of filamentsper crosssection. Another object is to provide multifilament yarnresembling spun staple in its desirable lightness, coveringeffectiveness and warmth-giving bulk but retaining the characteristiccontinuous filament freedom from loose ends, fuzziness and pilling.Another object is to provide bulky multifilament yarns of finer deniersthan can be spun practicably from staple. A further object is to providea process for preparing continuous filament yarn having a bulk equal orsuperior to that of comparable staple yarn without abrading or cuttingthe constituent filaments and without deforming or otherwise modifyingtheir structure. A still further object is to provide such a processwhich is suitable for rapidly and economically treating ordinarymulti-filament continuous yarn to greatly increase the bulk without theuse of moving mechanical parts other than in the windup. Yet anotherobject is to provide suitable apparatus for practicing the aboveprocess. Other objects of the invention will become apparent from thefollowing description and claims.

In this invention, a yarn fulfilling the above objectives has beneproduced, composed of a plurality of substantially continuous,individually convoluted filaments. The individual filaments have coils,loops or whorls at random intervals along their lengths. The mostobvious characteristics of the novel continuous filament yarn are itsbulkiness and the presence of a multitude of filament loops irregularlyspaced along its surface. These readily visible filament loopscontribute to bulkiness, but the less obvious convolutions of thefilaments within the yarn provide a lateral interfilament spacing whichis important in producing the bulk and resulting garment warmth offabrics made from this yarn.

The convolutions of the filaments may be held in place by the twistusually imparted to yarn. When this is done, the absence of internalstructural change may be shown by untwisting the yarn and taking itapart, whereupon the individual filaments will return to substantiallytheir original condition. When ordinary straight filaments are used toprepare the bulky yarn, substantially straight filaments are obtained byunbulking the yarn. Of course, crimped, wavy or curly filaments could beprocessed according to this invention, and such filaments would resumetheir respective starting configurations when separated from the yarn.Some reduction of tensile strength below that of ordinary continuousfilament yarn may be expected because, at any given point in the bulkedyarn of this invention, some of the filaments may not be placed undertension when the yarn is pulled, but this may be minimized or offset byincreased twist, production of the loop-within-a-loop configurationdescribed below, or by a treatment, such as steaming, to impart apermanent set.

A similar yarn might be prepared from a bundle of continous filaments bytedious hand manipulation. An individual filament would be separated andslack formed in the filament. The slack would be taken up by forming aminute coil or loop in the filament and holding it in place by twistingthe filament bundle or by encircling this loop by a similar convolutionformed in a nearby filament. Repetition of this operation at intervalsalong each and every filament could eventually give the desired yarnstructure.

In accordance with this invention a process has been devised forproducing the described yarn structure rapidly with surprisingsimplicity.

In the preferred process of this invention, a stream of air .or othercompressible fluid is jetted rapidly from a confined space to form aturbulent region. Yarn to be treated is fed into the fluid stream sothat the yarn is supported by it and the individual filaments areseparated from each other and whipped about violently in the turbulentregion. Merely removing these separatedfilaments from the turbulentregion for reassembly into a yarn accomplishes the desired result offorming loops and other convolutions at random intervals along eachfilament and irregularly spaced on different filaments. The filamentsare whipped about inthe turbulent zone sufiiciently to form convolutionsthat are retained during withdrawal, windup and further processing.

The invention will be better understood by reference to the drawings. Inthese drawings, which illustrate preferred embodiments of the invention,

Figure 1 is a schematic perspective view of suitable equipment formanufacturing bulky continuous filament yarn in accordance with theinvention,

Figure 2 is a side view showing the appearance of untreated yarn beingfed to the air jet (enlarged about ten times),

Figure 3 is a side view of the yarn leaving the air jet and being pulleddownward out of the turbulent zone (enlarged about ten times),

Figure 4 is a side view showing the appearance of treated yarn beforetwist is applied (enlarged about ten times),

Figure 5 is a side view showing the appearance of bulky yarn after twisthas been applied (enlarged about ten times),

Figure 6 is a graph showing how the yield point (initial loop-removaltension, measured as described below) increases with the twist appliedto bulky yarn,

Figure 7 is a side view of yarn treated by a modification of the bulkingprocess (enlarged about ten times),

Figure 8 is a modified form of air nozzle for use in practicing theinvention,

Figure 9 is another modification of nozzle,

Figure 10 is a further modification of nozzle,

Figure 11 is a still further modification of nozzle,

Figure 12 is a front perspective view of a two-deck uptwister machinemodified for practicing the invention,

Figure 13 is a schematic side view of the apparatus shown in Figure 12,

Figure 14 is a side view of another modification of apparatus suitablefor practicing the invention, and

Figure 15 shows the arrangement of filaments in a cross-sectional slicetaken through fabric woven from the bulky continuous filament yarn ofthis invention (enlarged about 50 times).

Referring to Figure 1, the continuous filament yarn to be treated may besupplied from any suitable source, such as a yarn package supported on acreel 21. Untwisted yarn will normally be used, but twisted yarn can beused satisfactorily by increasing the filamentseparating action, asshown later in the examples. The yarn can also be supplied directly fromthe spinning process by which it is produced, without any intermediatewind-up. The yarn 22, from whatever source is selected, passes throughguides 23 and 24, between feed rolls 25 and 26, and to air nozzle 27.This nozzle consists of a compressed air pipe 28 screwed or brazed intoyarn tube 29, shown partly in section. The pipe and tube are arranged atan angle so that a flow of air is produced through the tube sufiicientto carry the yarn along. The tube 29 can be as little as 1 inch long and0.05 inch inside diameter.

The appearance of the yarn entering the air jet 27 is shown in Figure 2.The filaments are relatively straight and closely packed, giving theyarn a rod-like appearance. As shown in Figure 3, the yarn leaving theair jet is blown apart by the air stream. High speed motion pictureshave shown that the individual filaments are whipped around violently bythe turbulent air. As the filaments are withdrawn from the region ofturbulence, they are swirled into convolutions which may be held inplace by adjacent filaments of the reforming yarn bundle. After passagethrough the turbulent zone and reforming into a yarn, the appearance ofthe bundle of filaments may be as shown in Figure 4. These fila- 4 mentsare only loosely grouped and a strong pull would remove the bulkiness ifit were not stabilized by additional treatment, preferably by twistingthe filaments together.

The loose bundle of filaments is directed by guides 30 and 31 to take-uprolls 32 and 33, and then passes to a wind-up device such as thedown-twister shown. As is usual with this device, the yarn is given atwist as it is wound by passing through a traveller guide 34 slidingaround on ring 35 mounted on ring rail 36. The yarn is collected onspindle 37, supported by spindle rail 38 and rotated by belt 39, to forma package of finished yarn 40. The appearance of twisted yarn producedin this way is shown in Figure 5. In the actual yarn loops may be lessthan 1 millimeter in size. The loops and other convolutions ofindividual filaments are firmly held in place by friction betweenfilaments. Increasing the twist increases this friction betweenfilaments and holds the convolutions more formly in place.

Figure 6 shows the effect of increasing amounts of twist on the yieldpoint of typical yarns. Yield point may be defined roughly as thetension required to initiate removal of the convolutions. It is measuredby tensioning the yarn and plotting points on the resulting stressstrain curve. At first, a steep, nearly straight line resultsrepresenting the elastic modulus. As slippage occurs, the pointsgenerally scatter about a less steep line. Prolongation of these linesresults in a point of intersection, and it is the stress at this pointthat is plotted as the ordinate in Figure 6. For the sample shown bycurve A, the yield point started at a low value of 20 grams for zerotwist, increased rapidly to a value of about 64 grams at a twist of 6turns per inch, and leveled oil? at a value of about 69 grams for twistsabove 10 turns per inch of yarn. The yarn used for the observations fromwhich curve A was drawn was made by the process of this invention fromdenier, 40 filament, 0 twist Acele (cellulose acetate yarn made by E. I.du Pont de Nemours and Company), using a feed rate of 28.9 yards perminute, an air pressure of 18 pounds per square inch gage, an air flowof 0.49 cubic feet per minute, measured at 760 mm. of mercury pressureand 70 F., and had a final denier of 190. For common textile denierssufficient resistance to ordinary tensions can be provided by a yieldpoint of at least 0.15 gram per denier, although higher values arepreferable.

If desired, yarn of the type shown in Figure 7 may be formed thatrequires little or no twist to provide relatively high yield points. Thereason for the increased stability of this product is the frequentoccurrence of snarls formed by entangled loops, e. g., a frequentencircling of the nodes of loops by other loops, most clearly seen atpoints a, b, and c in Figure 7. An attempt to stretch this modified yarnwill cause tightening of many of the encircling loops, thus preventingencircled portions from unlooping, and holding the filament bundletogether. As shown by curve B of Figure 6, at zero or low twist theyield point of this yarn is much higher than that of the simple productshown in Figure 5. The yarn tested to determine curve B was preparedfrom the same 150 denier, 40 filament, 0 twist Acele acetate yarn usedin connection with curve A, and under identical conditions except thatthe air pressure was increased to 25 pounds per square inch gage, givingan air flow of 0.55 cubic feet per minute. The final denier wasincreased to 205 as a result of the more complex yarn structure shown inFigure 7.

Yarn having the snarled orentangled loop structure is produced by acompounding of the ordinary looping action. This may be brought about inany one or more of a number of ways such as increasing the length oftime the yarn is within the turbulent zone, increasing the turbulence inthe zone, or setting up variations in the extent of turbulence.Adjustment of conditions to vary the bulky yarn produced according tothis invention from the form shown in Figure to the more complexstructure of Figure 7, or to any intermediate configuration, must bedetermined by experiment in a particular case.

In the process of this invention it is only necessary for the yarn to bepassed through a zone of sufiicient turbulence for a sufiicient distanceto separate the filaments and form them into the described convolutions.The yarn need not be passed through an air jet or nozzle of the typesdescribed, but can be passed through a turbulent stream, however formed.Likewise, air need not be used as the turbulent medium; other gases orliquids can be used. Piezoelectric or magnetostrictive transducers mightbe employed with similar effect, but the fluid jet method is soinexpensive and easy to install, operate and maintain, that it isnaturally preferred, as the best known mode of operation.

The extremely simple air nozzle 27, shown in Figure 1, is adequate toaccomplish effective yarn treatment as described above. However,smoother operation and more efficient use of air is provided by themodification shown in Figure 8, in which a stream-lined air nozzle 41 isprovided in place of the simple yarn tube 29 of Figure 1. Automaticthreading or stringing up is assured by addition of yarn guiding member42 having a conical inner end 43 through which the yarn end can beintroduced into the air stream in position to be carried with the airthrough nozzle 41. This member is threaded at 44 into a supporting body45, providing for adjustment of the distance between cone end 43 andinlet end of air nozzle 41. Air is fed to the nozzle through pipe 28.

In the nozzle shown in Figure 9, the air is introduced into a centralchamber 49 within the nozzle, passes from the chamber through a helicalpassageway formed by screw member 50, which gives the air a swirlingmotion, and leaves the nozzle through an orifice 51. It is convenient toform this orifice in a plug 52 screwed into the nozzle body. Althoughnot necessary, it is sometimes desirable to break up and deflect thejetted stream of air, as with a baffle 53, which is merely a plate bentat rightangles and attached to the nozzle with a screw 54. The yarn isconducted through screw member 50 to the vicinity of the orifice by atube 55 and is caught up by the air stream and carried out of theorifice. The best diameters for the tube and orifice will depend on theyarn being treated. For yarn of about 100 to 400 denier, satisfactorydiameters are 0.023 inch inside diameter for the tube and about 0.04inch for the orifice. The screw member 50, which supports the tube 55,is threaded into the nozzle body. The clearance between the inner end ofthe tube and the orifice is adjusted by the distance the screw member isturned, a hex nut 56 being attached or formed integrally on the outerend of the member for this purpose. When a satisfactory adjustment hasbeen found the screw member is locked in position by a hex nut 57. Theouter end of tube 55 is preferably flared to receive the yarn and whenstringing-up. Proper adjustment will make the jet self stringing, i. e.when an end of yarn is placed in the flared inlet of the tube the airstream will provide sufiicient vacuum to pull the yarn through the tubeand then blow it out of the orifice, greatly simplifying the starting upoperation.

The nozzle shown in Figure offers advantages in more efi icient use ofair, ease of adjustment to optimum conditions, and a single nozzle maybe used for processing a wider variety of yarns without adjustment. Thehousing 60 may be a standard inch plumbers T. The yarn enters throughguide member 61, provided with a funnel-shaped portion 62 to receive theyarn end when stringing up. The hypodermic needle 63 of appropriate sizeprovides a passage for conducting the yarn into the nozzle 64. Thenozzle has the shape of a conventional venturi tube with the entrance 65tapering inward so that opposite sides are at about a 20 angle with eachother, and the exit 66 diverging more gradually so that opposite sidesare at about a 7 angle with each other. The

overall length of the venturi tube may suitably be about 1.3 inches withthe diverging exit portion about 1.0 inch long. The arrangement of guidemember 61, needle passage 63 and nozzle 64 makes the deviceself-stringing when a yarn end is fed to it.

The needle 63 is adjusted to extend into the entrance of the venturi andstop in the venturi throat 67. This adjustment is important for bestperformance. The manner of adjustment shown is to thread the outside ofthe nozzle and provide positioning and locking nuts 68, 69. The nozzleslides with a snug fit into the housing 60 until nut 68 rests againstthe housing. It is held in this position by springs, one of which isindicated at 70. The guide member 61 likewise slides into the housingwith a snug fit until shoulder 71 is positioned against the housing. Itmay also be held in position by spring 70 and other similar springs.Advantages for this construction are that it can be taken apart easilyfor cleaning and the parts can be rotated to adjust the needle in theventuri throat. However, either or both parts may be held in position byset screws passing through the housing, or the parts may be threadedinto the housing as in Figure 9.

Air is supplied to the nozzle through pipe 72, which is threaded orsoldered into the T housing. The air passes through the venturi aroundthe needle 63, the venturi throat 67 being sufi'iciently larger than theneedle to permit passage of therequired volume of air. Gasket materialmay be placed in groove 73 around member 61 and groove 74 around thenozzle to prevent air leakage.

Figure 11 shows another modification which requires no adjustment to getthe yarn guide needle properly positioned in the nozzle 80. Except forthe internal design of the nozzle, the construction may be identicalwith that described in connection with Figure 10 and will not beredescribed. The principal air passage 81 through the nozzle has thesame shape as the diverging portion of the venturi described above, butthe throat 82 fits snugly around the yarn tube or needle 83. Little orno air can pass around the needle. Instead, the air is led past theneedle to the shart of the diverging portion of passage 81 through aplurality of small holes 84 drilled at a forward angle through the baseof the nozzle. Two such holes are shown, but six or more holes equallyspaced around the throat 82 are desirable.

The performance of the air jet may be improved by providing foreccentric operation on the yarn. The holes 84 in Figure 11 may be ofunequal size, be spaced unevenly, and/or be drilled at different angles.The yarn guide needle may be off-center in the venturi throat, anadjustment which is quite simply made with the type of nozzleconstruction shown in Figure 10.

The process has been specifically illustrated as used in connection witha downtwisting operation. However, it will be obvious to one skilled inthe art that the process may be practiced in conjunction with other yarnprocessing operations. Thus by similar simple modifications of existingequipment, the process can be practiced on an uptwister, a cottonspinning frame or in spooling operations. As mentioned earlier, twistedyarn may be processed as well as untwisted yarn. If the yarn already hasall of the twist desired, the yarn from the bulking treatment would becollected with a simple rewinder instead of a downtwister.

An adaptation of the equipment and process for use with an uptwister isillustrated in Figures 12 and 13. A portion of a conventional two-deckuptwister machine is shown in Figure 12 after modification bysubstitution of a bulking nozzle for each spindle in the upper deck. Theoperation is made clear from the schematic side view shown in Figure 13.The starting yarn 91, wound on spindle 92 in the lower deck, is passedthrough pig-tail guide 93, finger guides 94, and is metered to the airjet nozzle 90 after one or more wraps around a rough rubber-covereduptwister bobbin 95, which is surface driven by lower drive roll 96. Theyarn is passed through a pig-tail guide 97, mounted at the lower edge ofthe oil drip plate 98, and into the nozzle 90. The air, supplied to thenozzle through pipe 99, loops and tangles the filaments of the emergingyarn to form a bulky yarn as previously described. The yarn is pulledaway from the nozzle at right angles to the air stream through pig-tailguide 100. It passes through the fivefingered tension guide 101 and istraversed and wound into package 102 in conventional manner on winduproll 103, which is surface driven by roll 104.

The above arrangement provides a good degree of flexibility inoperation. Since the lower deck position is used as the feed system andthe upper deck position is used for windup, the two can be variedindependently to provide the required yarn speed and overfeed(difference between yarn feed and windup) for the desired bulkingtreatment. These are important because increased speed increases thefilament loop size and decreases the number of loops per unit length,while the amount of overfeed places an upper limit on the amount ofbulking which can be accomplished. The tension guide 101 provides africtional drag so that the yarn can be withdrawn from the nozzle 90under a low tension suitable for a high degree of bulking and yet bewound under a higher tension which is sufiicient to impart a highstability to the yarn and provide a firm package. For example, the yarnmay be drawn up to or more as it is being rewound while the otherconditions of speed, overfeed air pressure, etc., remain suitable toprovide a 30% increase in denier. The degree of twist imparted to theyarn can be adjusted by changing the speed of spindle 92. If the yarnalready has the desired amount of twist, the spindle can be keptstationary, or the yarn can be supplied in any of the ways usual foryarn processing generally.

For a. more positive control of overfeed and draw, the tension guide 101can be replaced with driven draw feed rolls similar to the nozzle feedrolls 95 and 96. Such a modification is shown in the machine of Figure14. The draw feed rolls are indicated at 105 and 106. Tension gauge 107indicates the tension applied. A rewinder 108 suitable for windingpackages of 2 pounds or more has been substituted for the conventionaluptwister windup roll. A yarn cleaner 109 is shown adjacent to theentrance of the nozzle to prevent it from being plugged by knots orloose fibers on the yarn. This may simply have a slit barely largeenough to accommodate the yarn. In other respects the component partsare similar in construction and operation to those shown in Figures 12and 13, and will not be redescribed.

A fairly abrupt removal of the yarn from the turbulent region isconductive to formation of a better product. This may be accomplished byguiding or pulling the yarn from the turbulent stream, as described, orthe turbulent stream may be diverted from the yarn by suitable meanssuch as a bafile plate having a hole to admit the yarn. The baffle plate53 in Figure 9 may be provided with a hole through which the yarn ispassed, the air stream being deflected aside by the plate. The rate ofwindup as compared with the rate at which yarn is supplied to the jet,will limit the amount of bulking action possible by restricting theamount of reduction in length which occurs as the loops form.

The air pressure required depends upon the type of nozzle, the type ofyarn, the yarn speed and the effect desired. In general, it is easier toobtain yarn uniformity when high air pressures are used, but the cost ofcompressing air makes it desirable to operate near the minimum pressurewhich will give adequate uniformity. Higher pressures are required forhigher yarn speeds, but economics favor higher speeds because the aircost per pound of product drops off rapidly as the through-put isincreased. Use of a wide range of air pressures is illustrated in theexamples which follow. The simple nozzle shown in Figure 1 requiredquite high air pressures. Quite low air pressures were used with thenozzle shown in Figure 9, but both of these nozzles were relativelyineflicient, in the amount of air used per pound of product, incomparison with'the diffusor type of nozzle shown in Figures 8, l0 and11. Typical air requirements for nozzles of the latter type whenprocessing yarn at speeds of 50 to yards per minute is about 40 poundsper square inch and between 2 and 4 cubic feet per minute at standardtemperature and pressure. Similar observations apply when using othergases or vapors such as steam.

The process and products of the invention will now be illustrated by thefollowing examples, which are not to be construed as limiting the scopeof the invention:

EXAMPLE 1 Apparatus equivalent to that in Figure 1, and using the nozzleshown in Figure l was used to process denier, 40 filament, 0 twist, dullAcele cellulose acetate yarn. The yarn was unwound for treatment from aspool by the tension created by the fluid jet, with a friction tensiondevice interposed between the spool and the nozzle to limit the yarnspeed to approximately 13 yards per minute (calculated from the windupspeed and ratio of final denier to starting denier). The nozzle wassupplied with nitrogen at 150 pounds per square inch gage pressure,giving a gas consumption of approximately 0.4 cubic feet per minute at760 mm. and 70 F. The yarn was wound up at 10 yards per minute andtwisted to 6 turns per inch with an up-twister. The finished bulky yarnhad a denier of and the average filament loop size was about 0.5 mm.

The yarn treatment was repeated with different gas pressures anddifferent yarn speeds to show how the size of the filament loops wasaffected. The changed conditions and the resulting loop sizes are givenin Table I; The loop sizes are compared qualitatively because they aredifficult to classify numerically. Generally speaking, however, V. S.(very small) means that most of the loops were less than 0.5 mm. insize, small means'that the predominating loop size was about 0.40 to0.75 mm., medium means that the predominating loop size was about 0.5 to1.5 mm., and large means that most of the loops were over 1.5 mm. insize.

Table I EFFECT OF VARYING OPEgtTING CONDITIONS ON LOOP EXAMPLE 2Apparatus of the type shown in Figure l, but using the nozzle shown inFigure 9, was used to process 150 denier, 100 filament, 0 twist, dullAcele yarn. The yarn was fed to the air jet at 21 yards per minute andrewound after treatment at 18 yards per minute at a spindle speed of5800 R. P. M. to impart a Z twist of 9 turns per inch. The air pressurewas 5 lbs/sq. in. and the air consumption 0.21 cu. ft./min. The finishedyarn had a denier of 175, a tenacity of 0.71, and an elongation of20.9%. Untreated 8 Z twist yarn had a denier of 150, a tenacity of 1.2,and an elongation of 26.

EXAMPLE 3 Apparatus of the type shown in Figure 1, but using the nozzleshown in Figure 9, was used to process 200 denier, 80 filament, 0.32twist, bright yarn of Orion acrylic fiber. I The yarn was fed to the airjet at 27.5 yards per The finished yarn had a denier of 258, a tenacityof 1.98 5

and an elongation of 17.6. Untreated 6 Z twist yarn had a denier of 200,a tenacity of 4.0 and an elongation of 19.

EXAMPLE 4 Apparatus of the type shown in Figure 1, but using the nozzleshown in Figure 9, was used to simultaneously blend and process 150denier, 60 filament, 2 S twist, bright textile Cordura viscose rayonyarn and .150 denier, 40 filament, twistdull Acele cellulose acetateyarn. The two yarns were unwound from separate spools and fed togetherto the air jet at 21 yards per minute. The treated blend was rewound at18 yards per minute and a spindle speed of 5820 R. P. M. to impart a 9 Ztwist. The air pressure was 10 lbs/sq. in. and the air consumption was0.25 cu. ft./min. The finished yarn blend had a denier of 342, atenacity of 0.74, and an elongation of 12.7. A similar blend which hadnot received the bulking treatment had a denier of 300, a tenacity of1.27 and an elongation of 16%.

In Examples 1 to 4 the treatment increased the denier by 30.0%, 16.7%,29.0% and 14.0%, respectively. This is some indication of the extent towhich filaments have been formed into convolutions, but does notindicate the surprising increase in bulk which these convolutions impartto the yarn by maintaining the filaments in spaced relationship. Ingeneral, this increase in bulk is at least 80% for packaged yarn, asshown by the following two examples EXAMPLE 5 Apparatus of the typeshown in Figure 1, but using the nozzle shown in Figure 8, was used toprocess 75 denier, 30 filament, 0.3 Z twist, bright yarn of Orlonacrylic fiber. The yarn was fed to the air jet at 54.0 yards per minute,treated with air supplied at 80 lbs/sq. in., and rewound after treatmentat 45.0 yards per minute with a 3 S twist. The yarn was wound on a quilladapted for accurate measurement of volume at a tension of 20 grams. Theyarn bulk was 3.3 cc./ gm. as compared with 1.2 cc./ gm. for theuntreated yarn, or an increase in bulk of 175%. The bulk was markedlysuperior to that of otherwise comparable spun staple yarn.

EXAMPLE 6 Apparatus of the type shown in Figure 1, but using the nozzleshown in Figure 8, was used to process 150 denier, 0 twist dull Acelecellulose acetate yarn. Two plies of this yarn were fed simultaneouslyto the air jet at 21.6 yards per minute, treated with air supplied atlbs/sq. in., and the combined treated yarn was rewound at 18.0 yards perminute with an 8 Z twist under a tension of 68 grams. The yarn bulk was2.0 cc./gm. as compared with 1.1 cc./gm. for the untreated yarn, or an.increase in bulk of 82%, even though the yarn was wound underconsiderable tension.

Since the purpose in treating yarn in accordance with this invention isto improve properties of fabrics in which it is used, the most practicalWay of showing the increase in bulk achieved is by observation made onsuch fabrics.

EXAMPLE 7 Fabrics were prepared in a 2 x 2 twill Weave from untreatedcontinuous filament viscose rayon yarn, from bulky yarn produced bytreating the yarn in accordance with this invention, and from stapleyarn spun from out filaments. A comparison of the results is given inTable II. The bulk was measured by ASTM Method D-76-49 at 3 lbs./ sq.in. with an Ames gage.

' 1 0 Table 11 COMPARISON OF memos WOVEN FROM TIIREE vIsoosE RAYON YARNSDenier Fabric 'lhick- Weight, Bulk, Type of Yarn of Yarn Count ness Inoz./ cc./gm.

Inches sq. yd.

Untreated 300 63x 60 0.013 5.01 1.9 Treated 340 64 x 68 0.021 5. 95 2. 6Spun Staple 313 68 x 62 0.0195 5. 65 2. 6

EXAMPLE 8 Table III COMPARISON OF FABRICS WOVEN FROM THREE DIFFERENTYARNS OF ORLON ACRYLIC FIBER Denier Fabric Thick- Weight, Bulk, Type ofYarn of Yarn Count ness In 02.] 0c./gm.

' Inches sq. yd.

UntreatezL 100 81 x 72 0. 006 2. 12 2.1 Treated 125 80 x 64 0. 015 2. 364. 8 Spun Staple. 133 93 x 60 0. 0125 3. 32 2.8

The results of Examples 7 and 8 show the marked superiority in bulk offabrics woven from the yarn of this invention in comparison with fabricswoven from ordinary continuous filament yarn. In general the increase inbulk is at least 30% when measured under the severe conditionsdescribed. The results also show that the bulky yarn may be equal, oreven markedly superior, to spun yarn in this respect. The way in whichthe filaments are spaced is shown visually in Figure 15. Fabric woven ofbulky yarn was immersed in methyl methacrylate and the monomer waspolymerized to hold the filaments in position. Then a cross-sectionalslice 50 microns thick was .cut from the fabric. The slice was too thinto show the filament convolutions as such, but the reproduction of aphotomicrograph of the slice in Figure 15 clearly shows the effect whichthe convolutions have in keeping the filaments spaced apart.Intersections of loops with the plane of the cut appear as irregularlyshaped dots.

Bulky yarn can be prepared by the process of this invention from anycontinuous textile fibers regardless of their origin. However, since thefilament convolutions of each filament are held in place by adjacentfilaments, the process is operative only with multifilaments. Theminimum number of filaments which can be processed satisfactorily intobulky yarn varies with the fiber, depending upon such factors assmoothness of surface, denier per filament, and the bending modulus, butany of the continuous multifilament materials referred to as yarn in thetextile trade can be prepared in this bulk form. The process describedhas been applied successfully to the production of bulky yarn from awide variety of commercial fibers, as indicated in Table IV. In thistable the starting material is designated by numbers indicating the yarndenier, the number of filaments and the twist in turns per inch,respectively, the type of twist, if any, and the trade designation. Thedesignation nylon refers to polyhexamethylene adipamide and polythenerefers to polymerized ethylene fibers. Orlon, Acele," and Dacron aretrade-marks of E. I. du Pont de Nemours and Company for acrylic,cellulose acetate and polyester fibers, respectively. Vinyon N is avinyl chloride-acrylonitrile copolymer produced by Union Carbide andCarbon Corp. Fortisan is a high tenacity rayon regenerated by saponi- 11fication of cellulose acetate and produced by the Celanese Corporationof America. Fiberglas is spun glass produced by Owens Corning FiberglasCorp. The nozzle shown in Figure 8 was used in the examples of Table IV,

The examples of Table V were performed with the nozzle shown in Figure.10, using the apparatus shown in Figures 12 and 13 for all except theexamples having package sizes of 1.0 and 1.5, respectively, where thewith the indicated air pressure given in lbs/sq. in. gage. similarapparatus shown in Figure 14 was used. The The air consumption is in cu.ft./min. at 760 mm. and 70 percent overfeed appearing in the table wascalculated as. F. Yarn speed is in yards per minute. follows:

Table IV W Overfeed (percent) 100) BULKY YARN PREPARATION FROM VARIOUS WMATERIALS where F is the rate of feed of yarn to the bulking nozzle, ExYam sgeed Air Air Fingl here determined by the surface speed of feedrolls 95 N 0 ta Materlfll Feed S Demer and 96 of the apparatus used, andW is the rate of windup p of the treated yarn. The difference in the twospeeds 7H4yZNy10n results from the shortening of the yarn in the bulking9---{ 2 50 35 52 286 treatment, hence the percent overfeed is anindication 10-. 50 41 52 0. 05 159 of the percent increase in bulkinessaccomplished by the process. This will become evident by comparing the11 82 66 52 0.66 161 12 50 38 48 1 2O 80 imtial and final demers withthe percent overfeed 1n 13" V D 3% 2g 0. g2 22 Table V.

14-. 40-34- 28 acr0n.. 2 1 1...

15 n 24 18 50 1 247 The percent instab hty s an indication of how well150-40;0 A0ele. the yarn will process in knitting and weavingoperations.

16-- 61i6 6 g 24 18 50 1.25 240 It was determined by suspending apreload of 0.01 gram 17" {4%1i Z Y1 or 150 112 50 0'71 212 25 per denierby a length of the yarn measuring 1 meter as 18 M j f g 50 36 40 L06 46preloaded, increasing the load to a total of 0.5 gram per 3" 2881-28-8jc gelgl n it; g 28 gig denier for 5 seconds, reduc ng the load to 0.05gram per g/lg l g n g g 1: 1g 223 denier, and measuring the finallength. The percent 22 280-136- yon...

23" 289 136 y;Z Dacronnm 48 42 60 L25 301 increase in length is thepercent instability given in the $89 222 fif g It IS important that thebulked yarn be stabilized against {100-50-0 vise. Ra g' l lni} 38 26 68203 such permanent deformation under the stresses it will 26" {%gg:g:g'%g gg ':i} 3s 26 68 1.28 243 encounter in processing and use. The yarnleaves the 101%50-0 Vise. Ray0n air jet under little or no tension, andsome of the convolu-. 27-- HM/Z 3s 25 58 1.28 201 28 Raw a Silkuhjj: 2119 76 L34 149 35 t1ons introduced are easily removed even from yarnhav-3303 0 522 gym N. 5 1 it; 2g is: mg a high twist. One way to stabilizethe yarn is to u 1 H y 4 311: 108-60 Oaeg1 i 1 3... 1 2( prestress itunldler a greater tension that it Wlll subsequently 32 110-115 ierg es"encounter. is removes convo utions which are not 33.- 66-20-7Z P 1 th 2118 41 1.0" 75 i we sufiiciently firmly locked in place but, of course,also reduces the bulkiness. The process as illustrated has EXample 4 has111l1tfated flppllcatlofl of the bulking included this prestressing as apart of the Windup operatreatment to yarn having an initial twlst of 2turns per tion. Thus, in the examples of Table V, the bulked yarn TableV BULKING TREATMENT APPLIED T0 TWISTED YARN Mat ial "Dacron "DacronDacron Nylon N 1 11 N 1 n N 1 Y Starting Denier 70 140 210 40 y 70 ZO 2%Nylgg 2 00 B33383 Acetglgg Filamen 34 68 102 34 34 34 55 102. 272 so 5080 Twist (T. P. 1., z)--. .5 .5 .5 .5 .5 5.0 .5 5.0 5.0 5.0 5.0 5.0 FeedSpeed (Y. P. M. 45 45 45 45 45 100 45 300 05 45 45 45 Windup Speed (Y.P. M.) 34 34 34 34 34 as 34 250 34 34 34 Overieed (percent).-. 33 33 3333 33 20 33 20 33 33 33 33 Final Denier omina 90 180 270 50 90 84 250250 700 250 390 400 Instability (percent). 6 4 2. 3 2. 3 2 2 2. 2 5. 32. 2 2 0 Air Pressure s. 1.)..- a0 35 40 40 40 35 40 70 40 2a '23 AirConsumption (C. F. M.) 2.2 2.5 2.6 2.5 2.5 2.5 2.5 4 2.5 1 5 1 7 1 5Needie Size (1. 1)., 0.001 in.) 10 10 10 2s 15 10 20 1e 20 '20 510 '20Venturi Throat (0.001 in.) 70 70 70 70 60 70 60 70 70 70 70 SpindleSpeed (R. P. M.) 7, 300 7, 300 7, 300 7, 300 7, 300 0 7, 300 .0 0 0 0 0Twist Added (turns)... 4.5 4. 5 4. 5 4. 5 4. 5 0 4. 5 0 0 0 0 0 PackageSize (lbS.) 25 25 4 5 25 1. 0 25 1. 5 25 25 25 .25

i and mp e 30 and 33 (Table 0 60 is stressed during passage from thetension guide 101 llustrated applicati n Of t tr t to y having to thewindup roll 103 (Figure 13), or between the draw initial twists of 3, 3and 7 turns per inch, respectively. The feed roll 105 (Figure 14) andthe windup roll. When other examples have been concerned with treatmentof using a downtwister, as illustrated in Figure 1, the yarn yarnsh'avlng from to /2 turns per inch of twist lmis stressed during passagefrom take-up rolls 32, 33 to mediately after bulking, and have rehedupon the windup the downtwi ter,

device to introduce the desired twist, a dOWntWi ter bei g Suchprestressing sometimes reduces the effectiveness disclosed for thispurpose. Table V further illustrates of the bulking treatment by anundesirable amount. The pp of the process to several yp of y s whlchstability can be improved by increasing the twist, but h ve a tw t ofabout 5 turns per inch as they enter the low twist yarns are oftenrequired. When applying the bulklng nozzle- Thls 15 adequate twlst 9111051111865, bulking treatment to yarn which has been twisted, as 50they do not need to be lEWlStEd after bulking. In half with theuptwister adaptation described, a knotty or of these examples thestarting yarn had the desired final nubby yarn will be produced if thetwist'is too high, altwist, while in the remalnder the desired twist wasintrothough this effect may sometimes be desirable. The enduced with anuptwister before bulking as indicated in tangled loop structurediscussed in connection with Figure the next to last line. 7 providesimproved stability, and this may be obtained by using lower yarn speedsor higher air pressures or higher over-feeds. These all involve changesin operating conditions, which may not be desirable. Stress-bearingfilamentscan also be used to provide stability, e. g., unbulkedfilaments can be plied with bulked yarn, or some of the filamentspassing through the air jet can be kept under such tension that littleor no bulking of these stress-bearing filaments occurs. That is, a groupor bundle of filaments can be fed to the air jet at a lower rate, e. g.,at substantially the speed of the windup device, than the rest of thefilaments, thereby keeping such group of filaments under tension andpreventing the formation of loops therein.

Bulky yarn may be stabilized after production by treating it with size,wax, heat or chemicals to set the convolutions or hold them in place.Various procedures known to the prior art may be adapted to thispurpose, and filaments may be set so firmly in the bulked configurationthat they will retain their convolutions even though the twist,initially used to hold it in place, is removed.

The proper use of sizing has been found to make low twist yarncompletely stable against loss of bulk during further textileprocessing. For example, a 70-34 /z 2 nylon yarn was bulked 33% andsingle end sized in a continuous operation, depositing 8% of polyacrylicacid size on the yarn in the form of a 10% aqueous solution with a sizeroll rotating at 4 revolutions per minute in a direction opposite to theyarn. This yarn was completely stable to stresses up to the breakingtension. When woven as filling yarn in a 70-34 continuous filament nylonwarp, no loss of bulk in fabric form and no difierence in pileresistance was noted in comparison with the same starting yarn bulkedand twisted to 86345 2. These two yarns were also knitted into socks,which were finished and dyed. The hand, bulk, covering power and runresistance of the /2 twist, sizedyarn socks appeared to be superior tothat of the corresponding socks knitted of unsized 5 Z twist yarn.Single end sizing of bulked yarn should be accomplished before windupbecause loss of bulk occurs when removing the unsized bulky yarn from apackage. An alternative method is to apply the size to the yarn package.

Heat-setting, especially steaming, effectively improves stability.Appropriate temperatures and procedures for a given material will besimilar to treatments used in the prior art for twist or fabric setting.As an illustration, a 70-34-5 2 nylon was bulked at 33% overfeed andheat set by three methods:

(a) Hot air at 160 F. wet bulb, 170 F. dry bulb, for

2 hours,

(b) Steam at 227 F. for 90 minutes,

(0) Steam at 274 F. for 1 hour.

The amount of instability, determined as previously described, wasreduced about 30% by treatment (a) and about 60% by treatment (b).Treatment (c) gave a somewhat better product and the treatment time wasshorter.

Regenerated cellulose filaments which will crimp spontaneously whentreated with a swelling agent are disclosed in U. S. Patent No.2,515,834 to W. D. Nicoll. Bulky yarn formed with these filaments in theuncrimped condition will have the bulkiness improved by crimping thefilaments as described in the patent, as by immersion in a warm diluteaqueous solution of caustic. Crimping in this way is also simplerbecause the filaments will crimp satisfactorily with the bulky yarnunder tension whereas the filaments ordinarily have to be relaxed (freeof tension) when crimped.

Table IV has illustrated the preparation of blended yarns by feeding twodifierent types of yarns simultaneously to the air jet. Any number ofyarns may be combined in this way. A uniform blend of diiferent types offilaments can be prepared during the bulking treatment with no moredifficulty than when bulking yarn from a single source. This is animportant advantage because of the increasing recognition being given toblends as a way of obtaining combinations of desirable textileproperties not obtainable with a single type of fiber. Yarn composed ofa mixture of staple fibers has been easy to prepare by conventionaltextile methods, but has been difiicult to accomplish with continuousfilaments. Since the bulky yarn of this invention will compete with spunstaple for many uses, it is fortunate that uniform mixtures are soeasily prepared.

A different purpose for mixing two difierent fibers arises whenpreparing very low denier bulky yarns. If the yarn denier is too low tobulk satisfactorily it can be bulked in combination with a secondmaterial which is then removed with a solvent which does not affect thefirst material. For example, a 30 denier, l0 filament, bulked nylon yarnwas found quite difficult to prepare from nylon alone with a givenequipment. It was readily prepared by bulking a 10 filament nylon yarnsimultaneously with a 30 filament acetate yarn to obtain a denier bulkedyarn and then removing the acetate filaments from the mixture bydissolving them in acetone. A mixture of fusible and infusible fiberscould be processed in a similar way, using heat instead of a solvent.

Even when bulking a single type of fiber it is sometimes desirable tofeed yarn simultaneously from more than one source of supply. In thisway larger yarns can be built up. Furthermore, since knots will notordinarily pass through a bulking nozzle, bulked yarn prepared from asingle source will be limited in length by the length of yarn on thesupply package. By feeding from more than one package, arranged so thatthe packages are not exhausted at the same time, bulked yarn can be madeof any desired length by starting a new package as soon as a yarn end isreached.

This application has been primarily concerned with the production ofuniform bulky yarn composed of continuous filaments. However, a numberof novelty effects may be obtained by changes in the air flow. By usinghigher pressures to obtain high jet velocities a yarn structure wasprepared which had the appearance of a hybrid between bulky continuousfilament yarn and a staple yarn. Sufiicient force was applied to breaksome of the filaments so that both loops and free ends were in evidence.With still higher velocity jets, all of the filaments are broken toproduce flock particles which may have a wide range of lengths. Whenusing extremely low jet velocities and overfeeding a knotty or nubbybulky yarn is produced. The knots are randomly spaced at intervals ofabout inch to 3 or more inches, depending on the conditions, and consistof complete convolutions of the entire yarn bundle except for a fewfilaments wrapped about the intersections with sufficient tenacity toimpart stability. A thick and thin yarn, wherein the thick sectionscontain most of the convolutions, is produced by a pulsating air jet.Most of the above novelty effects are accentuated when treating amixture of different types of filaments.

The most practical designs of air nozzles known have been disclosed, butthe process is so flexible that a wide variety of nozzles can be usedmore or less satisfactorily. letting devices which depart more widelyfrom those shown include multiple orifices or multiple venturis andcombinations of air jets in succession to accentuate the bulking action.The turbulence of the jet may be increased by cross jets. The filamentseparation may be accomplished or supplemented by other means, such asan electrostatic field to induce like charges on the filaments, causingthem to separate and balloon outward.

The advantages of this invention are many. The bulky yarn has thedesirable properties of spun staple yarn and avoids the necessity ofcutting continuous filaments into staple and then reforming the stapleinto yarn. The

15 bulky yarn is simply and economically prepared, by a process whichrequires little equipment, directly from the continuous filament bundleinitially produced in synthetic-fiber manufacture. The bulky yarn issuperior to spun staple for many purposes because of its freedom fromloose ends. However, it can be made to resemble spun staple in thisrespect, if desired, by cutting or singeing the protruding filamentloops to provide loose ends. The unmodified hand of fabrics made fromthe bulky yarn usually is stifier than that of corresponding staplematerials, making them more suitable for use in draperies, suits,overcoats, etc.

The yarn is sufficiently uniform to be handled easily by textilemachinery and to form highly uniform fabrics without the sacrifice ofbulk or of fiber interlocking characteristic of some mechanicallycrimped yarn having too regular a structural pattern. The yarn has beenused without difliculty on both automatic weaving and automatic knittingmachines. The increased covering effectiveness of fabric made with thebulky yarn permits the production of more fabric from the same weight ofyarn and, in addition, by greatly extending the utility of artificialfibers, enables them to replace expensive or scarce fibers in many uses.

Another advantage is the suitability of this process to combiningfilaments of extremely fine denier into light bulky yarns, having ahighly uniform appearance, for which there is no spun staplecounterpart. More than one kind of filament may be processedsimultaneously to create yarns with a desirable blend of fibercharacteristics. Intermittent impulsing of the multifilament beingprocessed can be used to produce a novelty yarn having alternatingsmooth lengths and bulked regions produced according to the describedprocess.

The simplicity of the new process permits its use at any point in yarnmanufacturing or winding with no interruption of processing routine andlittle outlay for new equipment. Distinct advantages of the process arethat it requires little supervision, demands very little maintenancebecause of its freedom from moving parts, and does not involvetemperature or humidity control.

Since many different embodiments of the invention may be made withoutdeparting from the spirit and scope thereof, it is to be understood thatthe invention is not limited by the specific illustrations except to theextent defined in the following claims.

What is claimed is:

1. A process for making bulky continuous filament yarn from a bundle ofsubstantially straight continuous filaments which comprises passing thefilament bundle through a fluid jet, jetting the fluid with suflicientforce to separate the filaments and form the filaments individually intoconvolutions, and removing the filaments from the jetted fluid andcombining the convoluted filaments into a yarn while avoiding tensionsuflicient to remove the convolutions. 2. A process for making bulkycontinuous filament yarn which comprises jetting a stream ofcompressible fluid rapidly from a confined space to form a turbulentregion, feeding continuous filament yarn into the fluid stream so thatthe yarn is supported by the stream and the individual filaments areseparated and whipped about violently in the turbulent region, removingthe filaments from the turbulent region with resultant formation ofconvolutions, and reassembling the filaments into yarn while avoidingtension sufiicient to remove the convolutions from the filaments.

3. A process for making bulky continuous filament yarn which comprisespassing a bundle of filaments through a high velocity air jet underconditions such that the filaments are separated and whipped aboutsutficienb ly to form convolutions, removing the filaments abruptly fromthe air jet, twisting the filaments together to form a yarn, andthroughout the process avoiding tension 16 which would straighten outthe convolutions of the filaments.

4. Apparatus for making bulky continuous filament yarn which comprises afluid nozzle adapted to create a turbulent zone, means for feeding yarncontinuously through the turbulent zone, means for supplying fluid tosaid nozzle under a pressure which will provide suificient turbulence toseparate the yarn filaments and form them into convolutions, and meansfor withdrawing the separated filaments from the turbulent zone andreforming them into yarn.

5. Apparatus for making bulky continuous filament yarn which comprises afluid nozzle adapted to jet a stream of fluid to form a turbulent zone,means for feeding yarn continuously into the fluid stream to pass withthe stream into the turbulent zone, means for supplying fluid to saidnozzle under a pressure which will provide suflicient turbulence toseparate the yarn filaments and form them into convolutions, and meansfor withdrawing the separated filaments from the turbulent zone andreforming them into yarn.

6. Apparatus for making bulky continuous filament yarn which comprises asource of yarn to be treated, feed rolls for supplying the yarn fortreatment at a controlled rate, an air nozzle adapted to pass the yarnthrough the nozzle with an air stream, means for supplying air to thenozzle under a pressure which will provide a zone of turbulence beyondthe nozzle sufiicient to separate the yarn filaments and form them intoconvolutions, take-up rolls for withdrawing the separated filaments fromthe turbulent zone, and yarn Winding means for twisting the filamentsinto a yarn and Winding the yarn into a package.

7. A process for making bulky continuous filament yarn which comprisespassing a bundle of filaments through a high velocity air jet underconditions such that the filaments are separated and whipped aboutsuificiently to form convolutions, removing the filaments abruptly fromthe air jet and collecting the bundle of filaments in orderly form on atake-up device without imparting additional twist to the bundle offilaments, said bundle of filaments having suificient twist to set saidconvolutions therein.

8. A process for making bulky continuous filament yarn which comprisespassing a bundle of filaments through a high velocity gas jet underconditions such that the filaments are separated and whipped aboutsufliciently to form convolutions, removing the filaments abruptly fromthe gas jet, twisting the filaments together to form a yarn, andthroughout the process avoiding tension which would straighten out theconvolutions of the filaments.

9. A process for making bulky continuous filament yarn which comprisespassing a bundle of filamentsthrough a high velocity air jet underconditions such that the filaments are separated and whipped aboutsufliciently to form convolutions, removing the filaments abruptly fromthe air jet, and reassembling the filaments into yarn while avoidingtension sufl'icient to remove the convolutions from the filaments.

10. A process for making bulky continuous filament yarn which comprisespassing a bundle of filaments through a high velocity fluid jet in amanner such that the jet operates eccentrically on said bundle offilaments and under conditions such that the filaments are separated andwhipped about sufliciently to form convolutions, removing the filamentsabruptly from the fluid jet, and reassembling the filaments into yarnWhile avoiding tension sufficient to remove the convolutions from thefilaments.

ll. Apparatus for making bulky continuous filament yarn which comprisesa fluid nozzle having a venturi throat adapted to create a turbulentzone, means for feeding yarn eccentrically with respect to said venturi17 18 throat and continuously through the turbulent zone, ReferencesCited in the file of this patent means for supplying fluid to saidnozzle under a pressure UNITED STATES PATENTS which will providesuificient turhulence to separate the 2,379,824 Mummery July 3, 1945yarn filaments and form them lnto convolutlons, and means forwithdrawing the separated filaments from the 5 FOREIGN PATENTS turbulentzone and reforming them into yarn. 816,215 Germany Oct. 8, 1951 UNITEDSTATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No; 2,852,906September 23, 1958 Alvin Lo Breen It is hereby certified that errorappears in the printed specification of the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 2, line 21, for "hens" reed been 3 column 4, line 19,. for"formly" read firmly column 5, line 69, for "The" read A =5 column 6,line 41, for shart' read start column '7, line 52, for "conductive" readw conducive column 13, line 33, for "pile" reed pill =--a Signed andsealed this 23rd day of December 1958,

(SEAL) Attest: I

KARL I ROBERT c. WATSON Attesting Oflicer Commissioner of Patents

1. A PROCESS FOR MAKING BULKY CONTINUOUS YARN FOR A BUNDLE OFSUBSTANTIALLY STRAIGHT CONTINUOUS FILAMENTS WHICH COMPRISES PASSING THEFILAMENT BUNDLE THROUGH A FLUID JET, JETTING THE FLUID WITH SUFFICIENTFORCE TO SEPARATE THE FILAMENTS AND FORM THE FILAMENTS INDIVIDUALLY INTOCONVOLUTIONS AND REMOVING THE FILAMENTS FROM THE JETTED FLUID ANDCOMBINING THE CONVOLUTED FILAMENTS INTO A YARN WHILE AVOIDING TENSIONSUFFICIENT TO REMOVE THE CONVOLUTIONS.
 4. APPARATUS FOR MAKING BULKYCONTINUOUS FILAMENTS YARN WHICH COMPRISES A FLUID NOZZLE ADAPTED TOCREATE A TURBULENT ZONE, MEANS FOR FEEDING YARN CONTINUOUSLY THROUGH THETURBULENT ZONE, MEANS FOR SUPPLYING FLUID TO SAID NOZZLE UNDER APRESSURE WHICH WILL PROVIDE SUFFICIENT TURBULENE TO SEPARATE THE YARNFILAMENTS AND FORM THEM INTO CONVOLUTIONS, AND MEANS FOR WITHDRAWING THESEPARATED FILAMENTS FROM THE TUBULENT ZONE AND REFORMING THEM INTO YARN.